Integrated circuits are widely available in a number of well-known packaging types, including wire-bonded lead packages (e.g., flat packs), ball grid arrays (BGAs; e.g., fine pitch BGAs). Frequently, manufacturers or suppliers of semiconductor and/or integrated circuit products (hereinafter, “integrated circuit(s)” or “ICs”) may wish to provide ICs otherwise having the same functionality and density in different packaging types. However, in general, such functionally identical ICs having different packaging types have, at least in part, a different product number and a different manufacturing flow. Usually, this is due to a perceived need to use a different mask for the uppermost level of metallization in order to form connections between pads on the IC to structures (e.g., ball bonds or wire bonds) that communicate with external devices.
For example, FIG. 1 shows a top-down view of an IC 100 having bond pads 110a-110z configured for wire bonding. In such a configuration, the wire bonds often have a sufficient inductance due to their length and/or proximity to other wires to induce cross-talk in neighboring wires. The wires can also act as small antennae, and thus be inadvertently affected by signals on nearby wires or other external sources. As a result, it is a common practice in wire-bonded IC packages to use several wire bonds to carry a common signal. Typically, this practice is used for power and ground wires, where even small fluctuations in the level of the signal can have dramatic effects in IC functions.
On the other hand, FIG. 2 shows a functionally identical IC 200 having bump pads 210a-210z configured for ball bonding. As is readily apparent, the locations of bump pads 210a-210z are not, as a whole, identical to the locations of bond pads 110a-110z in the IC 100 of FIG. 1, even though the functional circuitry is generally identical between IC 100 and IC 200. Also, the balls (or bumps) that form ball bonds generally do not have an appreciable or significant inductance, so ball bonds generally do not have an appreciable function or action as an antenna. Thus, a single ball bond can carry a power supply or ground signal to a particular location in IC 200, as opposed to the multiple wire bonds used in IC 100 of FIG. 1. Thus, the connection requirements (e.g., input and/or output signals and/or the descriptions thereof) may differ with different packaging options.
As a result, traditionally, two (or more) different versions of ICs are created when different packaging types are desired. This adds the cost of at least one additional mask to produce the different packaging version of the device. It also complicates product inventory management, as the IC packaging decision has to be made at the beginning of wafer production. A need therefore exists to create a single design and/or layout that provides the ability to select one of a number of different packaging types, which will, in turn, reduce the number of masks in making a related family of products, reduce manufacturing costs, simplify product inventory management, and enable greater flexibility with regard to meeting market demands for products having a certain packaging type.